//
// Created by yangchao on 2022/5/10.
// 70. 爬楼梯: https://leetcode.cn/problems/climbing-stairs/
//

#include <vector>
using namespace std;

class ClimbStairs{
public:
    int climbStairs(int n) {
        if (n <= 2) return n;
        vector<int> dp(n);
        dp[0] = 1;
        dp[1] = 2;
        for (int i = 2; i < n; ++i) {
            dp[i] = dp[i-1] + dp[i-2];
        }
        return dp[n-1];
    }
};

